1  // Copyright (c) 2011-2022 The Bitcoin Core developers
 2  // Distributed under the MIT software license, see the accompanying
 3  // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 4  
 5  #include <key_io.h>
 6  #include <rpc/util.h>
 7  #include <util/message.h>
 8  #include <wallet/rpc/util.h>
 9  #include <wallet/wallet.h>
10  
11  #include <univalue.h>
12  
13  namespace wallet {
14  RPCHelpMan signmessage()
15  {
16      return RPCHelpMan{"signmessage",
17          "\nSign a message with the private key of an address" +
18            HELP_REQUIRING_PASSPHRASE,
19          {
20              {"address", RPCArg::Type::STR, RPCArg::Optional::NO, "The bitcoin address to use for the private key."},
21              {"message", RPCArg::Type::STR, RPCArg::Optional::NO, "The message to create a signature of."},
22          },
23          RPCResult{
24              RPCResult::Type::STR, "signature", "The signature of the message encoded in base 64"
25          },
26          RPCExamples{
27              "\nUnlock the wallet for 30 seconds\n"
28              + HelpExampleCli("walletpassphrase", "\"mypassphrase\" 30") +
29              "\nCreate the signature\n"
30              + HelpExampleCli("signmessage", "\"1D1ZrZNe3JUo7ZycKEYQQiQAWd9y54F4XX\" \"my message\"") +
31              "\nVerify the signature\n"
32              + HelpExampleCli("verifymessage", "\"1D1ZrZNe3JUo7ZycKEYQQiQAWd9y54F4XX\" \"signature\" \"my message\"") +
33              "\nAs a JSON-RPC call\n"
34              + HelpExampleRpc("signmessage", "\"1D1ZrZNe3JUo7ZycKEYQQiQAWd9y54F4XX\", \"my message\"")
35          },
36          [&](const RPCHelpMan& self, const JSONRPCRequest& request) -> UniValue
37          {
38              const std::shared_ptr<const CWallet> pwallet = GetWalletForJSONRPCRequest(request);
39              if (!pwallet) return UniValue::VNULL;
40  
41              LOCK(pwallet->cs_wallet);
42  
43              EnsureWalletIsUnlocked(*pwallet);
44  
45              std::string strAddress = request.params[0].get_str();
46              std::string strMessage = request.params[1].get_str();
47  
48              CTxDestination dest = DecodeDestination(strAddress);
49              if (!IsValidDestination(dest)) {
50                  throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Invalid address");
51              }
52  
53              const PKHash* pkhash = std::get_if<PKHash>(&dest);
54              if (!pkhash) {
55                  throw JSONRPCError(RPC_TYPE_ERROR, "Address does not refer to key");
56              }
57  
58              std::string signature;
59              SigningResult err = pwallet->SignMessage(strMessage, *pkhash, signature);
60              if (err == SigningResult::SIGNING_FAILED) {
61                  throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, SigningResultString(err));
62              } else if (err != SigningResult::OK) {
63                  throw JSONRPCError(RPC_WALLET_ERROR, SigningResultString(err));
64              }
65  
66              return signature;
67          },
68      };
69  }
70  } // namespace wallet